ROLE OF IRON IN HUMAN HEALTH
NATIONAL AGRI-FOOD BIOTECHNOLOGY INSTITUTE, MOHALI , PUNJAB, INDIA
WHY DO WE NEED IRON
Iron is a mineral found in every cell in
It is vital for both physical health and
Iron has three main functions :
carrying oxygen from the lungs to the rest of
maintaining a healthy immune system.
(Body protects itself from antigens, which includes virus, bacteria and
foreign substances that make sick)
aiding energy production.
(Iron is constituent of several enzymes including : iron catalase,
peroxidase, and cytochrome enzymes)
INSUFFICIENT DIETARY IRON CAN
RESULT IN IRON DEFICIENCY
more frequent infections
reduced resistance to cold
TYPES OF IRON
There are two types of iron in food:
Heme iron, derived from the hemoglobin and myoglobin
found in meat tissue
Non-heme iron, derived mainly from cereals,
legumes, fruit and vegetables.
Heme iron is found only in animal foods. The iron in
meat is approximately 40% heme iron and 60% non-heme
iron. Plant foods do not contain any heme iron .
Heme iron is well absorbed and relatively unaffected by other
It is influenced to some extent by the body’s iron stores.
The average absorption of heme iron in meat is about 25%.
Non-heme iron is found in plant foods.
It is not as well absorbed as heme iron and is affected
by both the iron status of an individual, and components
in foods eaten at the same time.
Absorption of non-heme iron can vary from under 1% in
an individual with replete stores to 20% in an individual
with depleted iron stores .
Generally non-heme iron absorption is less than 5%.
VITAMIN C IMPROVE NON-HAEM
Vitamin C can increase the absorption of non-haem
iron by two to three times.
There is a dose-related effect; the more vitamin C in a meal, the greater
the iron absorption - up to a limit of around 100mg vitamin C .
Vitamin C is found in fruit and vegetables. Both heat and air reduce
vitamin C content, so care should be taken when cooking and storing fruit
FACTORS AFFECTING NONHAEM IRON ABSORPTION
TANNINS IN TEA
MEAT, FISH, POULTRY
PHYTATES IN WHOLEGRAINS
CITRUS FRUIT (ORANGES, GRAPES) OXALATE
Iron supplements should only be used when advised
by a dietitian or prescribed by a medical practitioner for
diagnosed iron deficiency.
Iron supplements should be used
cautiously as they may interfere with the absorption of
other nutrients such as zinc and calcium.
HEME IRON UPTAKE
LIBERATED WITH IN ENDOSOME
NON-HEME IRON UPTAKE
HEPCIDIN REGULATES IRON
Hepcidin is 25 amino-acid peptide hormone.
Hepcidin is synthesized by hepatocytes.
Hepcidin binds to ferroportin1 and causes
its internalization and degradation thereby
decrease iron transfer to blood.
Hepcidin function to regulate(inhibit)
iron transport across gut mucosa there by
preventing normal iron level.
Hepcidin regulation by
IL-6 a prominent inducer of hepcidin, through
STAT-3 dependent transcriptional mechanism.
Other cytokines may also induce hepcidin independent of IL-6.
Macrophage also express hepcidin in response to
Hepcidin may function in autocrine manner to degrade macrophage
causing local retention of iron in macrophages.
EFFECT OF MUTATION OF
Hypotransferrinanemia - recessive
TMPRSS6 mutation - IRIDA
HFE gene mutation
Ferroportin mutation – autosomal
H ferritin mutation - dominant
Heme iron are associated
cardiovascular diseases(CVD) risk.
Such as saturated fats or other dietary and
lifestyle factors associated with meat intake.
Hereditary hemochromatosis is inherited disorder that results
from an excess accumulation of iron in many organs which is
manifested by liver cirrhosis, cardiomyopathy, diabetes
mellitus, arthritis, skin pigmentation and if left untreated
The gene responsible for hereditary hemochromatosis is
closely linked to locus for the human leukocyte antigens and
has been identified as major histocompatibility complexencoded class-1 like HFE.
Hereditary hemochromatosis is more prevalent than other
inherited diseases such as cystic fibrosis, sickle cell anemia,
phenylketonuria and Tay-Sachs disease.
Farataxin is mitochondrial protein which involved in
mitochondrial iron homeostasis.
Farataxin deficiency is due to hyper-expansion of
polymorphic GAA trinucleotide repeat which
inhibits transcription and falls in levels of mature
Farataxin deficiency in patients leads to develop
Friedrich’s ataxia which is a progressive
neurological disorder and cardiomyopathy and
finally leads to death.
• Melanotransferrin reported to expressed in amyloid
plaques in brain of patients with Alzheimer’s
• Melanotransferrin mRNA widely expressed in tissue
and also in salivary glands.
• Levels of melanotransferrin mRNA do not change in
presence or absence of an iron chelators or iron
• Functional studies shown that melanotransferrin
transports iron from iron-citrate complexes but not
from iron-transferrin complex.
• Melanotransferrin has minor role in iron uptake from
iron citrate complexes.
IRON BIOAVAILABILITY IN
IRON IN /mg
Roasted Pumpkin and Squash Seeds
Sesame Butter(Tahim) and Seeds
Apples, without skin
Pears, without skin
IRON BIOAVALABILITY IN GRAINS
IRON IN /mg
Wheat Flour, White
Wheat, Soft White
Wheat, Hard White
Corn flour, Masa,
Corn flour, Masa,
Rice Bran, crude
MORE HEME IRON RICH
Beef Lean Chuck
Clams, Oysters and Mussels
IRON mg per Day
Infants (7-12 months)
Children (1-13 years)
Boys (14-18 years)
Girls (14-18 years)
Women (19-50 years)
Women over 50 years
Men over 19 years
Heme and non-heme iron are absorbed differently.
Meat, fish, poultry and vitamin C improve the
of non-heme iron.
Tannin, oxalate, phytates and dietary fibre all reduce the
absorption of non-heme iron.